The invention described herein relates generally to structures for measuring the thickness of tube walls and more particularly to structures for determining the deviation of the tube wall thickness from the known thickness of a selected standard item.
There are uses for tubes which require that the tube walls have a precise thickness. An example is the gold tubes manufactured by electrochemistry processes. Conventionally, ultrasonic and radiographic measurements have been made to determine tube thickness. However, repeatable measurements to within .+-.0.005 cm are difficult to obtain using these techniques. Furthermore, these techniques are time consuming and expensive. The tubes have to be transported from their fabrication facility to be measured. It is desirable to develop a measurement device that is portable and has improved accuracy and precision. Furthermore, conventional micrometers and calipers cannot be used to measure the thickness of a tube for its entire length because they cannot reach the internal middle portions of a tube much longer than a few centimeters.